Over the past nine years, patients with spinal muscular atrophy (SMA) have seen the number of FDA-approved treatment options for their disease go from zero to three. Now, an approval for a tablet formulation of Roche's Evrysdi can be added to the list of advances in this field over the span of a decade.
The FDA on Wednesday gave the thumbs-up to a 5-mg tablet formulation of Evrysdi (risdiplam) to treat SMA in adults and children ages 2 and older who weigh more than 44 pounds.
The approval, which was granted to Roche’s Genentech unit, should offer patients living with SMA greater flexibility in how they manage their disease, the company said in a release. Back in 2020, Evrysdi was approved as an oral solution taken by mouth or feeding tube.
The two other SMA stalwarts on the market, Biogen’s oligonucleotide Spinraza and Novartis’ gene therapy Zolgensma, are delivered intrathecally (into the cerebrospinal fluid around the spinal cord) and via a one-time, 60-minute infusion, respectively.
Roche says it plans to launch the new Evrysdi tablets—which can either be swallowed whole or dispersed in water—“in the coming weeks.”
SMA advocates were quick to celebrate the approval, with the Muscular Dystrophy Association (MDA) noting in a Wednesday release that the new Evrysdi presentation “expands treatment options, offering patients and families easier access to treatment and increased flexibility in managing SMA.”
“The approval of the tablet formulation of Evrysdi marks another major milestone for the SMA community, providing an easier administration method that enhances quality of life for people living with this disease,” Sharon Hesterlee, Ph.D., chief research officer at the MDA, said in a statement.
The FDA based its approval decision on results from a bioequivalence study showing that the 5-mg Evrysdi tablet provided comparable drug exposure versus the original oral liquid formulation, Roche said in its release. The company noted that it will continue to supply Evrysdi oral solution for patients on other doses of the drug and for those who prefer the liquid presentation.
Evrysdi, which was initially approved in August 2020, is designed to target the genetic root cause of SMA by boosting production of survival motor neuron (SMN) proteins in the central nervous system and peripheral tissues. SMN protein, which is lacking in patients with SMA, is found throughout the body and is essential to the function of nerves that control muscles and movement, according to Roche.
The medication has been growing steadily since its launch, with full-year Evrysdi sales growing (PDF) 18% to 1.6 billion Swiss francs (nearly $1.8 billion) in 2024.
Meanwhile, Biogen and Novartis have watched sales of their SMA assets dwindle in recent years.
For the final three months of 2024, Novartis’ Zolgensma sales fell 6% at constant currencies to $262 million, with sales for the year overall clocking in at around $1.2 billion. The gene therapy peaked in 2022 at $1.4 billion in annual sales and has gradually been declining ever since.
The situation is much the same over at Biogen, where total 2024 sales of Spinraza landed at $1.57 billion, down around 10% compared to the sum the drug generated in 2023.
Addressing Spinraza’s gradual downturn, Biogen CEO Chris Viehbacher stressed to investors Wednesday that the SMA field is a “very competitive market with a very limited number of patients.”
“The interesting thing is, how do you compete in a market like this?” Viehbacher opined during his company’s fourth-quarter earnings call. “We say, ‘OK, one pill a day beats two pills a day, a pill beats an injection,’ but the actual reality is, in a lot of these devastating diseases, it’s efficacy that matters.”
With that efficacy benchmark in mind, Viehbacher pointed to the potential boon a higher-dose version of Spinraza could provide SMA patients in the near future.
After reporting in September that a higher dose of Spinraza significantly improved motor function in newly diagnosed infants with SMA in a phase 2/3 trial, Biogen announced plans to submit global regulatory filings for the more potent formulation the following month.
“And that’s really the story of Spinraza,” Viehbacher said during Wednesday’s call. “The high dose, I think, will be important because you can get to the therapeutic levels of drug that you need much faster.”